president obama paid tribute to nelson mandela today. through his fierce dignity, an unbending will to sacrifice his own freedom for the freedom of others he transformed south africa and moved all of us. embodied the that countries can change for the better. his commitment for the power and reconcile with those who jailed him set an example for all humanity to aspire to, whether in the lives of nations or in our own personal lives. >>> i promised you the president of the united states, and he's here. let's play "hardball." ♪ >> it's my honor to introduce the president of the united states. >> hey. [ applause ] ♪ >> well, thank you, mr. president, and thank you, dr. neil kirk win is here, the president of the american university for having us here today. >> it's good to see you. >> so what brought you to "hardball"? >> american university. [ cheers and applause ]. >> "hardball" was just an excuse to hang out with these fine young people. i've had wonderful experiences here. the first time i spoke here actually was when i was running f